Gelled compositions in stick form are well known and have been used for various cosmetic and pharmaceutical applications. The gel sticks should be of such firmness that a reasonable amount of active ingredients is applied when the stick is rubbed over the skin. Transparent gel stick compositions are also known and may be preferred by consumers, perhaps because they regard the clarity as an indication of product purity or performance.
Thus, U.S. Pat. No. 4,759,924 to Luebbe et al discloses cosmetic stick compositions comprising about 40-70% of a polyhydric aliphatic alcohol; about 3-10% soap; about 1-20% hydroalcoholic soluble emollient and water, the emollient having the formula R(OC.sub.3 H.sub.6).sub.a (OC.sub.2 H.sub.4).sub.b OH wherein a/(a+b).ltoreq.0.5. Optionally, the compositions also may contain less than about 12.5% of a short chain monohydric alcohol such as ethanol and up to about 10%, preferably 1-5% of a water-insoluble emollient.
The water-insoluble emollients disclosed in the Luebbe patent are fatty esters, fatty ethers, alkoxylated fatty esters, fatty alcohols and low molecular weight silicone fluids. Typical materials include isopropyl palmitate, myreth-4, PEG-8-distearate, cetyl alcohol, dimethicone copolyol, cyclomethicone and dimethicone.
A clear stick formulation is also disclosed in de Navarre, The Chemistry and Manufacture of Cosmetics, Vol. IV, p. 697 (Second Edition 1975). The de Navarre composition contains 15% Pluronic F-127 (a polyoxyethylene, polyoxypropylene block copolymer); 7% sodium stearate; 68% propylene glycol and water. However, the de Navarre formulation does not contain a water-insoluble emollient. Moreover, the formulation of de Navarre is exceptionally hard.
Cosmetic gel stick compositions are also disclosed in GB 2,114,887, which compositions comprise 2-60% of an alkanol having 1-4 carbons; 2-50% of a diol having 4 carbons, and 2-15% soap, the composition having an average melting point of at least 50.degree. C. The compositions of the GB '887 application may also contain an ethylene oxide and/or propylene oxide condensation product of the formula H(C.sub.2 H.sub.4 O).sub.a (C.sub.3 H.sub.6 O).sub.b OR where R is either hydrogen or an alkyl group having from I to 20 carbons and a and b are each from 0 to 35, the sum of a+b not exceeding 35. There is no indication that the formulations of GB '887 are clear.
Gelled deodorant compositions are also disclosed in Appell, Cosmetics, Fragrances and Flavors, p. 62 (1982).
U.S. Pat. No. 4,268,498 to Gedeon et al discloses clear cosmetic sticks containing 2-5% polyoxyethylene (17-23)-glucose fatty acid ester; 2-5% polyoxyethylene (20-26) ether of a long chain alcohol; 24-72% polyoxypropylene (2-5) ether of a long chain alcohol; 5-8% sodium salt of a fatty acid; 5-10% propylene glycol; 5-10% lower alkyl ester of a fatty acid; 2-5% water, and 3-40% of a cosmetically active ingredient.
Aqueous gel compositions containing a water-insoluble pharmaceutically or cosmetically active organic ingredient employing as gelling agents certain polyoxyethylene/polyoxypropylene block copolymers are disclosed in Schmolka, U.S. Pat. No. 3,867,533. U.S. Pat. No. 4,089,814, also to Schmolka, discloses a roll-on perfume composition comprising per 100 parts by weight of composition, 5-15 parts essential oil; 25-40 parts alcohol; 20-40 parts certain polyoxyethylene-polyoxypropylene block copolymers, and 5-50 parts water.
A solid, transparent, gelled antiperspirant composition is disclosed in U.S. Pat. No. 4,154,816 to Roehl et al, the compositions of Roehl containing a lower monohydric alcohol, a di- and/or trihydric alcohol and/or a lower polyglycol, a propylene-ethylene glycol polycondensate having the formula HO(C.sub.2 H.sub.4 O).sub.x (C.sub.3 H.sub.6 O).sub.y H wherein y/(x+y)=0.6 to 1 and have a molecular weight of at least 500; dibenzaldehydemonosorbitol acetal; an antiperspirant compound, and mono- or dialkylolamide of a higher fatty acid.
Cosmetic stick compositions containing an active are also disclosed in U.S. Pat. No. 4,226,889 to Yuhas, the compositions containing by weight 1-30 parts sodium stearate; 100 parts water and the active material. Preferably, the composition also contains a polyhydroxyl compound such as a glycol or polyglycol in an amount of from 0.5-10% by weight of the composition.
U.S. Pat. No. 4,346,079 to Roehl discloses antiperspirant compositions containing dibenzaldehyde-monosorbitol acetal as a gelling agent and up to only about 10% of propylene-ethylene polycondensate. A solid antiperspirant stick composition is also disclosed in U.S. Pat. No. 4,425,328 to Nabial, the base compositions containing hydrophobic waxy matrixes including a volatile silicone emollient, the level of which may be reduced by incorporation of certain liquid polyoxypropylene-alkyl ethers.
U.S. Pat. Nos. 4,382,079 and 4,440,742, both to Marschner, disclose deodorant stick compositions containing a bicarbonate. In addition to the bicarbonate, the Marschner compositions contain a soap-based gel comprising 20-90% polyhydric alcohol gelled by about 2-15% of an alkali metal salt of a C.sub.14 -C.sub.20 saturated fatty acid. Other optional ingredients include soaps, emollients and emulsifiers such as silicones, fatty esters, fatty amines, fatty alcohols, ethoxylated fatty alcohols and acids, thickeners and bacteriostats. The compositions of Marschner are said to be clear, notwithstanding the incorporation of the bicarbonate. Thus, the composition of Example 16 containing 8% potassium bicarbonate is reported to have similar appearance to the composition of Example 15, which has no bicarbonate.
Clear aqueous gels prepared from certain polyoxybutylene-polyoxyethylene block copolymers are disclosed in U.S. Pat. No. 4,465,663 to Schmolka. Cosmetic sticks comprising polyhydric aliphatic alcohols, ethylene oxide and/or propylene oxide condensation products, and soap are disclosed in U.S. Pat. No. 4,504,465 to Sampson et al.
A nonstaining antiperspirant stick composition is disclosed in U.S. Pat. No. 4,511,554 to Geria et al. Other antiperspirant/deodorant stick compositions are disclosed U.S. Pat. No. 4,524,062 to Laba et al and U.S. Pat. No. 4,720,381 to Schamper et al. Clear acid stable dibenzyl monosorbitol acetal gels are disclosed in U.S. Pat. No. 4,725,430 to Schamper et al. A transparent gel base is disclosed in GB 1,207,438, the composition comprising 47-75% of a mixture of alkylene oxide block polymers and fatty alcohol polyethylene glycol ethers and/or alkyl-phenol-polyethylene glycol ethers. Cosmetic gels are also disclosed in GB 2,020,974 A and GB 2,114,887 A.
A nonaqueous deodorant stick composition is disclosed in Canadian Patent 1,196,867 to Geria.
Notwithstanding the array of prior art in the field of cosmetic compositions, the gel compositions designated as clear or translucent do not have the degree of clarity desirable in such products. Moreover, many of the prior art products tend to become cloudy or hazy after standing for a period of time. Typically, the haziness becomes progressively worse, so that after about a month or so the product is quite cloudy and can be said to have little or no transparency. Inasmuch as products such as these are often warehoused for one or more months subsequent to manufacture, the length of time the product retains at least the major portion of its transparency is an important characteristic.
Another problem associated with gelled sticks of the type herein disclosed in the formation of crystals over time. These crystals are particularly noticeable in view of the clarity of the product, and are believed caused by impurities contained in the soap component.